Ch 4: Lipids: Types, Functions, and Health Impacts in Human Nutrition

Lipids

Diverse, vital functions in body.

Triglyceride

3 fatty acids & 1 glycerol backbone.

Saturated Fatty Acids

Contain H atoms, single bonds, harder, spoils less fast.

Unsaturated Fatty Acids

No H atoms, double bonds, softer.

Monounsaturated Fatty Acids (MUFA)

1 double bond.

Polyunsaturated Fatty Acids (PUFA)

2+ double bonds, spoil fast.

Cis-Fatty Acid

Hydrogens on the same side of double bond (natural form).

Trans-Fatty Acid

Hydrogens on opposite sides (from hydrogenation).

Hydrogenation

Add H to double bonds, prevents spoilage.

Essential Fatty Acids

Omega-6 & omega-3 must come from food; essential nutrients.

Phospholipids

1 of 3 types of lipids, compounds similar to triglycerides with a phosphorous-containing acid.

Emulsifier

Mixes fat & water & part of cell membrane, used by food industry.

Sterols

One of main classes of lipids: large, complex molecules of carbon.

Cholesterol

Most common sterol; not essential, made by liver.

Plant Sterols

Reduce cholesterol absorption.

Fat Digestion

Breaks triglycerides into monoglycerides, fatty acids, and glycerol.

Energy Storage

Fat storage is unlimited compared to limited glycogen supply.

Resting Energy Needs

Fat provides 60% of resting energy needs.

Cardiovascular Disease

All diseases of the heart and blood vessels.

Saturated Fats

Raise LDL cholesterol, increasing risk of heart disease.

Trans Fats

Raise LDL & lower HDL; also promote inflammation.

Monounsaturated Fats

Lower LDL, protect heart.

Polyunsaturated Fats

Protect against heart disease.

Omega-3 Fatty Acids (EPA & DHA)

↓ triglycerides, ↓ clot risk, stabilize heartbeat, ↓ blood pressure, anti-inflammatory.

Fat-Soluble Vitamins

Vitamins A, D, E, K carried by fats.

Fat Replacers

Water/air, protein, fiber, olestra.